Ahsan Javed¹ and Krishna S Nayak^1
1Electrical and Computer Engineering, University of Southern California, Los Angeles, CA, United States

Arterial spin labelled cardiac magnetic resonance (ASL-CMR) imaging is a non-contrast myocardial perfusion (MP) imaging technique which can detect clinically relevant changes in MP under vasodilatory stress. Existing ASL-CMR techniques have limited spatial coverage because they cannot acquire multiple slices during the limited duration of pharmacologically induced peak stress (~3-4 min). In this work, we demonstrate the feasibility of a using carefully designed single shot echo planar imaging sequence for multi slice ASL-CMR at 3T.

Xiao-Qing Zhang¹, Meng-Chu Chang¹, Ming-Ting Wu², Ken-Pen Weng^3,4, and Hsu-Hsia Peng^1
1Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu, Taiwan, ²Department of Radiology, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, ³Department of Pediatrics, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan, ⁴Department of Pediatrics, National Yang-Ming University, Taipei, Taiwan

We aimed to investigate the abnormal aortic flow and its adverse interaction with regional myocardial motion in repaired tetralogy of Fallot (rTOF) patients. The rTOF patients were divided into rTOF1and rTOF2 groups according to their indexed right ventricular end-systolic volume (RVESVi). The rTOF2 group demonstrated increased aortic retrograde fraction and there was a correlation exhibited between retrograde fraction and systolic myocardial motion. In conclusion, the assessments of abnormal artic flow and altered myocardial motion were helpful in elucidating the possibly adverse interaction between the characteristics of the aorta and myocardium in rTOF patients with different degrees of RV dilatation.

Thomas Küstner¹, Aurelien Bustin¹, Olivier Jaubert¹, Radhouene Neji^1,2, Claudia Prieto¹, and René M Botnar^1
1Biomedical Engineering Department, School of Biomedical Engineering and Imaging Sciences, King's College London, London, United Kingdom, ²MR Research Collaborations, Siemens Healthcare Limited, Frimley, United Kingdom

Free-breathing continuous acquisitions, so called free-running, enable 3D whole-heart coverage for motion-resolved functional cardiac MRI. In prior work approaches based on 3D radial imaging were proposed with scan times of ~10-15min which also require computationally demanding reconstructions. In this work, we propose a 3D Cartesian free-running water-selective sequence that provides isotropic 3D whole-heart CINE imaging in <2min. Data is acquired with a variable-density spiral-like 3D Cartesian out-inward sampling and sequence-adaptive tiny-golden and golden angle increment. Respiratory motion-corrected and cardiac motion-resolved CINE images are obtained from a multi-bin-PROST reconstruction which exploits spatial-temporal redundancies. High agreement to conventional 2D CINE was observed.

Junyu Wang¹, Yang Yang^2,3, Ruixi Zhou¹, Changyu Sun¹, Mathews Jacob⁴, Daniel S. Weller⁵, Frederick H. Epstein^1,6, and Michael Salerno^1,3,6
1Biomedical Engineering, University of Virginia, Charlottesville, VA, United States, ²Biomedical Engineering and Imaging Institute and Department of Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, United States, ³Medicine, University of Virginia, Charlottesville, VA, United States, ⁴Electrical and Computer Engineering, University of Iowa, Iowa City, IA, United States, ⁵Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, United States, ⁶Radiology, University of Virginia, Charlottesville, VA, United States

First-pass contrast-enhanced myocardial perfusion imaging is a useful noninvasive tool to evaluate patients with known or suspected coronary artery disease, but current techniques are still limited in spatial-temporal resolution and ventricular coverage. We designed a spiral pulse sequence with simultaneous multi-slice (SMS) acquisition and utilized the SMS-L1-SPIRiT reconstruction technique to achieve ultra-high resolution (1.5 mm at 1.5 T and 1.25 mm at 3 T) perfusion imaging with whole-heart coverage. The proposed spiral SMS perfusion acquisition strategy was tested on heathy volunteers and clinical patients. High image quality was demonstrated with an SMS factor of 3 at both 1.5T and 3T.

Ye Tian¹, Jason Mendes¹, Brent Wilson², Alexander Ross², Edward DiBella¹, and Ganesh Adluru^1
1Radiology, University of Utah, Salt Lake City, UT, United States, ²Cardiology, University of Utah, Salt Lake City, UT, United States

We propose Continuous Radial Interleaved simultaneous Multi-slice acquisitions at sPoiled steady-state (CRIMP) for whole-heart, ungated, free-breathing myocardial perfusion assessment. The simultaneous multi-slice (SMS) sequence captures multiple cardiac phases in all image slices simultaneously and keeps the inner slices at steady-state. We use a patch-based motion-compensated locally low-rank method to reconstruct the images. Quantitative perfusion analysis was also performed with an arterial input function estimated from a separate low-dose injection.

Joao Tourais^1,2, Torben Schneider³, Cian Scannell⁴, Russell Franks⁴, Javier Sanchez-Gonzalez⁵, Mariya Doneva⁶, Christophe Schuelke⁶, Jakob Meineke⁶, Jochen Keupp⁶, Jouke Smink¹, Marcel Breeuwer^1,2, Amedeo Chiribiri⁴, Markus Henningsson⁷, and Teresa Correia^4
1MR R&D – Clinical Science, Philips Healthcare, Best, Netherlands, ²Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, Netherlands, ³Philips Healthcare, Guildford, Surrey, United Kingdom, ⁴School of Biomedical Engineering and Imaging Sciences, King’s College London, London, United Kingdom, ⁵Philips Healthcare Iberia, Madrid, Spain, ⁶Philips Research Europe, Hamburg, Germany, ⁷Department of Medical and Health Sciences, Linkoping University, Linkoping, Sweden

First-pass perfusion cardiac MR (FP-CMR) allows the detection of myocardial ischemia. Also, quantitative methods enable a reliable and operator-independent assessment of myocardial perfusion. However, conventional FP-CMR has limited spatial resolution and should be performed under breath-hold. Therefore, diagnostic accuracy is compromised by respiratory induced motion artifacts and false-positive defects due to dark-rim artifacts. We propose, a k-t accelerated dual-saturation FP-CMR multi-echo Dixon sequence to increase the spatial resolution, estimate respiratory motion from fat images and measure T2*-related signal loss from the multi-echo images. Thus, perfusion quantification is improved by minimizing dark-rim artifacts, correcting for respiratory motion and T2*.

Tim A. Jedamzik¹, Johannes Martens¹, Sabine Panzer¹, Maria Siebes², Jeroen P. H. M. van den Wijngaard^2,3, and Laura M. Schreiber^1
1Chair of Cellular and Molecular Imaging, Comprehensive Heart Failure Center (CHFC), University Hospital Würzburg, Würzburg, Germany, ²Dept. of Biomedial Engineering & Physics - Translational Physiology, Amsterdam UMC, University of Amsterdam, Amsterdam Cardiovascular Sciences, Amsterdam, Netherlands, ³Dept. of Clinical Chemistry and Hematology, Diakenessenhuis, Utrecht, Netherlands

To analyze systematic errors and regional variability of the myocardial blood flow (∆MBF) and myocardial perfusion reserve (∆MPR) estimates in dynamic contrast-enhanced perfusion MRI, computational fluid dynamic (CFD)-simulations were performed in a realistic 3D coronary vasculature model of an ex-vivo porcine heart. Simulations were performed down to the pre-arteriolar level for the myocardial segments. The simulations show a strong spatial variance in the resulting ∆MBF and ∆MPR values of up to 60%. The errors are increasing with distance from the model inlet as well as with lower flow velocities. Errors are more pronounced in the right coronary artery.

Lexiaozi Fan^1,2, Daming Shen^1,2, Hassan Haji-Valizadeh³, Nivedita K Naresh⁴, James C. Carr¹, Benjamin H. Freed⁵, Daniel C. Lee⁵, and Daniel Kim^1,2
1Department of Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States, ²Department of Biomedical Engineering, Northwestern University, Evanston, IL, United States, ³Department of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center & Harvard Medical School, Boston, MA, United States, ⁴Department of Radiology, University of Colorado Denver, Denver, CO, United States, ⁵Division of Cardiology, Internal Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, United States

Compressed sensing (CS) is capable of accelerating cardiac perfusion MRI for achieving high spatial resolution (1.6 mm x 1.6 mm x 8 mm) and extensive spatial coverage (6+ slices per heartbeat), but the lengthy image reconstruction time (~8 min per slice with 64 frames using GPU) hinders its clinical translation. In this study, we sought to, for the first time, rapidly reconstruct accelerated cardiac perfusion data using a 3D residual U-net for clinical translation.

Caroline M. Colbert^1,2, Anna Le³, Jiaxin Shao¹, Jesse Currier³, Peng Hu¹, and Kim-Lien Nguyen^1,2,3
1Department of Radiological Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States, ²Physics and Biology in Medicine Graduate Program, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States, ³Division of Cardiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States

T1 reactivity can be used as a marker for myocardial perfusion reserve in the setting of ischemia or hypoperfusion. We hypothesize that ferumoxytol, as a pure intravascular agent with high r1 relaxivity, sensitizes T1 reactivity for assessment of myocardial perfusion. We selectively induced acute myocardial hypoperfusion in twelve healthy male Yorkshire swine. We then performed native and ferumoxytol-enhanced adenosine stress testing with the MOLLI sequence at 3.0T. Ferumoxytol increased absolute T1 reactivity in remote regions by 4.62-fold. The normalized difference in T1 was 4.5-fold greater in FE images compared to native T1.